set L = QLTLattice1 ;

reconsider z = 0 as Element of QLTLattice1 by ENUMSET1:def 1;

reconsider o = 1 as Element of QLTLattice1 by ENUMSET1:def 1;

reconsider dwa = 2 as Element of QLTLattice1 by ENUMSET1:def 1;

dwa "/\" (dwa "\/" o) = dwa "/\" z by QLTEx1Def

.= z by QLTEx1Def ;

hence not QLTLattice1 is join-absorbing by LATTICES:def 9; :: thesis: verum

reconsider z = 0 as Element of QLTLattice1 by ENUMSET1:def 1;

reconsider o = 1 as Element of QLTLattice1 by ENUMSET1:def 1;

reconsider dwa = 2 as Element of QLTLattice1 by ENUMSET1:def 1;

dwa "/\" (dwa "\/" o) = dwa "/\" z by QLTEx1Def

.= z by QLTEx1Def ;

hence not QLTLattice1 is join-absorbing by LATTICES:def 9; :: thesis: verum